Three dimensional (3D) displays are becoming increasingly popular. Presently, many 3D displays implement stereoscopic techniques to generate a 3D visual display to a user. Such displays, which may be referred to as stereoscopic 3D displays, rely on the well known stereoscopic imaging technique for creating the illusion of depth in an image. As is generally known, stereoscopy is a method of creating a 3D image from a pair of two dimensional (2D) images, in which each of the 2D images preferably represents the same object or image from a slightly different perspective, such as a right eye perspective and a left eye perspective.
Referring to FIG. 1, a typical prior art stereoscopic display 102 is configured to generate a 3D representation of an image viewable by a viewer 104. A left eye 106 and a right eye 108 of the viewer 104 are focused on a focus plane 109 at the stereoscopic display 102 (the viewer 104 is a binocular viewer having two eyes separated by an interpupillary distance 110). A left stereo channel selection mechanism 112 is positioned between the left eye 106 and the stereoscopic display 102 and a right stereo channel selection mechanism 114 is positioned between the right eye 108 and the stereoscopic display 102. Two stereo perspective views, a left perspective view 116 and a right perspective view 118, of a single stereoscopic object or feature 120 are presented to the binocular viewer with a convergence plane 122 (perceived location) based on vergence. The distance between the focus plane 109 and the convergence plane 122 is a depth cue disparity 121. Stereo channel selection mechanisms 112 and 114 can take many conventional forms well known in the art, including polarized filters, colored filters, temporal shutters, and others. These selection mechanisms 112, 114 can also be incorporated as part of the display, for example using lenticular arrays or other mechanisms known in the art. The function of the stereo selection mechanisms 112, 114 is to cause the left eye 106 to see only left perspective view 116 and right eye 108 to see only right perspective view 118. When the viewer's gaze is directed at feature 120, the perceived depth, or distance from the viewer, of feature 120 is determined by the intersection or converging of the lines of sight from the eyes to their respective perspective views.
Stereoscopic display systems, which provide enhanced interpretation of the information by users over two dimensional displays and can result in improvements in performing various tasks as well as various other potential benefits, may be used for applications which rely on periods of extended concentration and/or critical information, such as avionics, medical, engineering/industrial or military applications, and may also be used for applications of shorter concentration periods, such as entertainment applications, for example, movies. Stereoscopic 3D displays have been conventionally directed toward intermittent and non-critical applications such as entertainment and modeling. One of the lingering concerns of use for extended periods or critical information is the human tolerance for the vergence-accommodation disparity present in these displays. Vergence refers generally to the relative inward angle of the two eyes to detect depth, whereas accommodation refers to the distance for which the eyes are optically focused. Under normal real-world circumstances of viewing actual objects (including most two dimensional electronic displays), the vergence and accommodation cues typically match. Both of these cues are valid 3D depth or distance cues, along with a number of other 3D cues, for example, motion parallax, occlusion, relative size, absolute size, linear perspective, and shading/shadows. Conventional stereoscopic displays achieve the sensation of 3D by manipulating vergence cues while having the eyes remain focused on a fixed display surface or screen. This disparity between competing depth cues can result in viewer fatigue and discomfort, especially over an extended period of time, and can potentially interfere with the benefits of using a stereoscopic display. The potential for fatigue, including eyestrain, headaches or other discomfort, is generally believed to be increased as the degree of mismatch increases and can potentially interfere with the benefits of using a stereoscopic display.
As the environment, such as aviation, in which these stereoscopic systems are used becomes more complex, it is preferable that the operator be attentive and receive information in a timely manner and with little stress (such as eye fatigue) to ensure proper operation. The user must interpret the information provided on the screen occupying his/her thought processes when he/she may have many other decisions to make.
Accordingly, it is desirable to provide a method and system displaying information stereoscopically that may be more easily understood by the user without taxing human tolerances. Furthermore, other desirable features and characteristics of the exemplary embodiments will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.